1. Field of the Invention
The present invention relates to a water color and more particularly to a water color which comprises a water-soluble hemicellulose as an effective component and has excellent coloring power and dispersion stability.
2. Description of the Related Art
Water colors have hitherto been produced by milling together a color pigment as a colorant, a colorless extender pigment, such as calcium carbonate or barium sulfate, a naturally occurring synthetic water-soluble polymer, such as gum arabic, dextrin or carboxymethyl cellulose, and water.
These water colors have a drawback that when they are filled into a tube or a container and allowed to stand for a long period of time, the water-soluble polymer is yellowed, which causes a change in hue of the water color to an unexpected one.
The use of naturally occurring gum substances, such as gum arabic, as the water-soluble polymer can provide water colors having the best properties in respect of coloring power and dispersibility of the pigment. However, the supply of the naturally occurring gum substances is susceptible to weather in production countries, so that the price fluctuation is large. For this reason, in recent years, naturally occurring gum substances, which can be stably supplied, have become strongly desired in the art.
As described above, when the water-soluble polymer as one component of the water color is used in final products, it should provide a good long-term dispersion stability. In this respect, the conventional water-soluble polymers do not always satisfy all the requirements.